Supplementary Material for: Real-life nationwide outcomes of bronchoscopic lung volume reduction with endobronchial valves in severe COPD

Introduction:
Chronic Obstructive Pulmonary Disease (COPD) is the third leading cause of death globally, characterized by airflow limitation and lung hyperinflation due to emphysema. Bronchoscopic lung volume reduction (BLVR) with endobronchial valves offers a minimally invasive treatment option for emphysema, aiming to reduce lung hyperinflation, thereby improving lung function and exercise tolerance.

Methods:
This study evaluated the efficacy of BLVR in a real-life nationwide setting using comprehensive Danish registries. The study population included patients who underwent BLVR between January 1, 2013, and December 31, 2021. We assessed clinical outcomes, including Forced Expiratory Volume in 1 second (FEV1), Medical Research Council (MRC) dyspnea score, and the rates of exacerbations and pneumonia before and after the procedure. A control cohort of matched COPD patients was also analyzed.

Results:
Following BLVR, a significant increase in FEV1, similar to the improvements reported in randomized controlled trials was observed. Additionally, the proportion of patients classified as GOLD stage IV decreased from 71.3% to 60.6% after BLVR. The incidence rate ratio for severe exacerbations significantly dropped to 0.56 (95% CI 0.47-0.67, p<0.01) after BLVR. No significant changes were observed in the rates of moderate and severe pneumonia, and mortality rates did not differ significantly from those in the matched control cohort.

Conclusion:
This study demonstrates the real-life efficacy of BLVR using endobronchial valves, highlighting a significant improvement in FEV1 and a reduction in severe COPD exacerbations. The procedure did not increase pneumonia rates or affect mortality, supporting continued use of BLVR for managing patients with COPD.

引言：
慢性阻塞性肺疾病（Chronic Obstructive Pulmonary Disease, COPD）是全球第三大死亡原因，其特征为气流受限以及肺气肿引发的肺过度充气。采用支气管内瓣膜的支气管镜肺减容术（Bronchoscopic Lung Volume Reduction, BLVR）为肺气肿患者提供了微创治疗选择，旨在减轻肺过度充气，进而改善肺功能与运动耐量。

方法：
本研究依托全面的丹麦登记数据库，在真实世界的全国性医疗场景中评估了BLVR的临床疗效。研究队列纳入2013年1月1日至2021年12月31日期间接受BLVR治疗的慢阻肺患者。我们评估了多项临床结局指标，包括一秒用力呼气容积（Forced Expiratory Volume in 1 second, FEV1）、英国医学研究理事会（Medical Research Council, MRC）呼吸困难评分，以及手术前后的急性加重与肺炎发生率。同时还分析了匹配的慢阻肺患者对照队列。

结果：
BLVR术后，患者的一秒用力呼气容积（FEV1）出现显著升高，这与随机对照试验中报道的改善结果一致。此外，被归类为GOLD Ⅳ期的患者比例从术前的71.3%降至术后的60.6%。严重急性加重的发生率比显著降至0.56（95%置信区间0.47~0.67，p<0.01）。中重度肺炎发生率未出现显著变化，死亡率与匹配对照队列相比也无显著差异。

结论：
本研究证实了支气管内瓣膜BLVR的真实世界疗效，凸显了其对FEV1的显著改善以及慢阻肺严重急性加重的减少作用。该手术并未增加肺炎发生率，也未对死亡率产生影响，支持继续将BLVR用于慢阻肺患者的临床管理。